The present invention relates to a non-volatile semiconductor memory suitable for high integration and a method for manufacturing the same.
Referring to a conventional non-volatile semiconductor memory shown in FIG. 6, an N-type drain region 1a and an N-type source region 1b are provided on the surface of a P-type semiconductor substrate 1. A three-layer film 36 is provided apart from the source region 1b through a gate insulating film 2 by a constant distance. The three-layer film 36 includes a floating gate 3, a layer insulation film 33 and a control gate 34. A side wall electrode 35 is formed between the source region 1b and the three-layer film 36.
With the above-mentioned structure, the optimum potentials are applied on the side wall electrode 35 and the control gate 34, respectively. As a result, electrons can be injected from the source side to the floating gate 3.
Referring to the conventional non-volatile semiconductor memory, a side wall is formed between the source region 1b and the three-layer film 36 having the floating gate 3 on a self-control basis and is used as the electrode 35. Consequently, the whole manufacturing steps are very complicated.